The Final Prophet by Mohammad Elshinawy

When the Quraysh tribe embraced Islam, they feared being blocked from their trade routes to Shām and Iraq, since these territories were under Byzantine and Sassanid rule and both had rejected the call to Islam. Jābir ibn Samurah  reports the Prophet صلى الله عليه وسلم addressing this concern by reassuring Quraysh that those empires would soon vanish from both regions. He said, “When Chosroes dies, there will be no Chosroes after him.

And when Caesar dies, there will be no Caesar after him. And I swear by the One in whose hand is Muhammad’s soul, their treasures will be spent in the path of God.”286 Imam al-Shāfi‘ī and al-Khaṭṭ ābī (d. 988) explained that this meant there would never be another Caesar in Greater Syria, nor any other Chosroes in Iraq (Sassanid Persia). Indeed, the final Chosroes who rose to power during the Prophet’s صلى الله عليه وسلم life was Yazdegerd III (d. 651), and he indeed became the 38th and final king of the Sassanid Empire. The final Caesar during the Prophet’s صلى الله عليه وسلم life was Heraclius (d. 641), and Byzantium did in fact collapse and lose Christendom’s holiest site of Jerusalem during his reign.

After those individuals, neither empire maintained any presence in those two regions.287